public function AddEndReminder(ReservationReminder $reminder)
 {
     if ($reminder->MinutesPrior() != $this->endReminder->MinutesPrior()) {
         $this->AddEvent(new ReminderAddedEvent($this, $reminder->MinutesPrior(), ReservationReminderType::End));
         parent::AddEndReminder($reminder);
     }
 }
 private function minutesValid(ReservationReminder $reminder)
 {
     $minutes = intval($reminder->MinutesPrior());
     return $minutes > 0;
 }